<script>
/*
 * @Author: wzh 
 * @Date: 2020-12-30 21:50:39 
 * @Last Modified by: 1521620993@qq.com
 * @Last Modified time: 2020-12-30 23:55:55
 */
</script>
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>01-脱离常规流的定位元素</title>
</head>
<body>
  <style>
    .item1{
      /* width: 100px; */
      height: 100px;
      border: 2px solid blue;
      position: relative;
      float: left;
    }
    .item2{
      width: 50px;
      height: 50px;
      background-color: red;
      margin: 6px;
    }
    .item3{
      background-color: red;
    }
  </style>
  <div class="box">
    <div class="item1"></div>
    <div class="item2">item2</div>
    <span class="item3">item3</span>
  </div>
</body>
</html>